Hello Group, I have a 1997 Hitachi ex220-3 with 7500 hours that overheats after about 20 minutes of hard work. So far, I cleaned radiator, replaced radiator fluid, put on a new water pump, changed all the hydraulic and oil flters. No luck so far. What should I try next. Hate to replace radiator without knowing it is the problem. Someone else on the forum replaced the DP sensor, but don't know if that is the logical next step. Any suggestions would be great. T. Wesson
thermostats
Get a non contact thermometer and tell us what you get for temperatures. I'm saving my guesses for a funner problem.
Check to ensure the impeller in water pump is not failed. fire engine and loosen a hose to see if coolent is under pressure. note any fluid leaking from front of pump common failure on Isuzu's and cummins
Water coolant pump is working proper ? check the coolant lines, any folds etc.
Some passages in rad could be blocked. The area of rad will be cool with infared temp tester. The extra water flowing through perhaps 75% of tubes will not give up enough heat to run cool. A compotempt rad shop can test and there are flow meters that mount in rad hose to check for adequate flow. Thermostats are good possibility especially with the bypass not properlly blocking at operating temp.
I once had an exhaust leak on a hoe drive me near crazy until I found it. It was blowing exhaust toward the radiator. It's not likely, but it's quick and free to check.
I had a 220-3 with the same problem the fan was on backwards ,make sure the cup in the blade is to the engine not the radiator . Like mitch said that one drove me crazy
Hello Group, Thanks for all the comments so far. I did put a new thermostat on - no luck. The coolant lines seem to be flowing good. I can check the temps at the bottom and top of the radiator tomorrow. I hate to pull the radiator without knowing that is the problem. Could it be something with the hydraulics? T. Wesson
hello wesson when heat up the machine stop all works and don't stop engine. full throttle the engine and check 10 minuets without operate the machine.if heat goes down your engine is ok if not check engine cooling system and engine head gasket condition. if heat goes down your machine has a hydraulics system problem then check following items hydraulic relief pressure hydraulic pump leakage rate hydraulic cooler bypass valve center swivel seal condition pilot pressure bonnet and engine room cushioning ok i hope your feedback good luck
I ran a 1995 270 Hitachi in Chicago area. Some of the 90 degree days it would over heat, we put the engine hood up and ran it like that. Not the best for the hood hinges, but it ran cool.
Did you ever find out what the problem was..,?
Hello. I did have a wheeled Hitachi excavator and it did have a heating problem, i newer owerheating bud it was close. On hot days i could only drive on roads 10 og 15 minutes until i have to stop and let it cool. I dit check everithing, thermo, rad, pump an so on, i notice a few time when i was checking on things that the battery who was in front of the coolers was really hot. One day when i was overthinking about this problem i did spot the problem. Under the coolers use to be a skid plate or protection plate, and it was not there anymore, and i could stick my hands both sides of the radiator. I did make a new skid plate under the coolers and i cut down a sponce matres from old bed and put on both sides of the radiator to seal the gaps, And the problem was solved. The problem was the air, the hot air would go in circles, from the radiator fan under and with the sides of the coolers and thro the coolers again and again and dit not draw a fresh air. Maybe it is this simple on your mashine.